1. Field of the Invention
The present invention relates to a magnetic head and a magnetic head assembly used for a high density recording/reproducing apparatus.
2. Description of the Related Art
Recently, in the high density magnetic recording and reproducing apparatus such as a video cassette tape recorder, there has been employed a multichannel system for simultaneously recording and reproducing information signals on and from a magnetic tape, wherein a plurality of magnetic heads are aligned parallel to each other in a tape running direction in a window provided in a rotary drum of the apparatus, and information signals are recorded and reproduced on or from a plurality of tracks on the magnetic tape by the plurality of magnetic heads by rotating the rotary drum together with the plurality of magnetic heads.
FIG. 1 is a partial front view showing a multichannel magnetic head assembly viewed from a head-tape contact surface side in the prior art.
Multichannel magnetic head assembly shown in FIG. 1, is employed, for instance, for simultaneously recording and reproducing the information signals on and from a magnetic tape (not shown). As shown in FIG. 1, both a recording magnetic head 1 having a magnetic gap 13 and a reproducing magnetic head 2 having a magnetic gap 23 are aligned parallel to each other on a head base 15 provided in a window 16 of a rotary drum 14 in such a manner that they are remote from each other at an interval D1 between the magnetic gaps 13, 23 thereof so as to allow the magnetic gaps 13, 23 to contact the magnetic tape upon a tape running operation.
Each of the recording and reproducing magnetic heads 1, 2 has a pair of magnetic core sections 11, 12, and 21, 22, and each of the pair of magnetic core sections 11, 12 (21, 22) is comprised of a pair of reinforcing members 12a, 12c (22a, 22c) and a magnetic core 12b (22b) interposed between the pair of reinforcing members 12a, 12c (22a, 22c) in a stacked manner.
The magnetic core section 11 of the recording head 1 has a length W1 which is the same as a length W1 of the magnetic core section 12 thereof, and the magnetic core section 12 of the reproducing head 2 has a length W1 which is the same as a length W1 of the magnetic core section 22 thereof as well.
The magnetic gap 13 of the recording magnetic head 1 is inclined at an angle .theta..sub.o to a line perpendicular to the head base 15 in a clockwise direction, and the magnetic gap 23 of the reproducing magnetic head 2 is inclined at an angle .theta..sub.o in a counterclockwise direction or the opposite direction to the magnetic gap 13.
In the simultaneous recording and reproducing system, there arises a crosstalk problem between the recording and reproducing magnetic heads 1, 2. To suppress a value of the crosstalk below a predetermined value, it is effective to extend the interval D1 between the magnetic gaps 13, 23 of the recording and reproducing magnetic heads 1, 2 or to provide a magnetic shielding member 17 between the recording and reproducing magnetic heads 1, 2.
The interval D1 is usually determined according to an electrical specification. Thus, it may be difficult to extend the interval D1. Even when it is possible to extend the interval D1, a too larger interval D1 causes a problem that the magnetic tape is slackened during the tape running operation. This slack of the magnetic tape prevents the recording and reproducing magnetic heads 1, 2 from securely contacting the magnetic tape, and causes a tape damage in a worst case.
As another countermeasure to suppress the value of crosstalk without extending the interval D1, it is effective to extend a distance between the magnetic core portions 12, 21 which are facing each other, by shortening the lengths W1 of the magnetic core portions 12, 21.
However, to shorten the lengths W1 of the magnetic core portions 12, 21 causes an other problem that a head wear characteristic of the recording and reproducing magnetic heads 1, 2 is degraded because of reduction of the head-tape contact areas thereof.